Originally posted by Just1MoreDave I hate to insult your intelligence, but it is a preset lens, so the aperture ring with the click-stops can be overridden by the ring that turns smoothly.
On my 135/3.5 preset, the front barrel unscrews rather easily and the blades are right there, but I don't know anything about the preset mechanism. With the value/rarity of the 83/1.9, I wouldn't want to learn on it.
Ah.... Now that you've state that it's a preset, guess i'm out coz i've never had a hand on opening up a preset lens. ;P
But yea, TS, a preset lens has 2 aperture ring:
First one acts as a limiter to your intended aperture.
Second one allows you to open or stop down the aperture as wide as your first aperture ring allows, or set to.
I might be wrong but i sure did try to play with my friends'..
Say, for sure it is rare, but if it is stuck wide open, what else can you do? It'll still be stuck wide open anyway.. LoL!
Nevertheless, just do a quick check that you are not "limiting" the aperture using the preset ring.. Not sure which one.. Haha!